Enabled Billing Plans and Agreements APIs

- Added API Classes, Samples, and Tests
- Updated Functional Tests
- Updated Documentation with new SDK Name
- Updated Few Samples to use newer nicer result page

sample/billing/SuspendBillingAgreement.php

@@ -0,0 +1,35 @@
+<?php
+
+// # Suspend an agreement
+//
+// This sample code demonstrate how you can suspend a billing agreement, as documented here at:
+// https://developer.paypal.com/webapps/developer/docs/api/#suspend-an-agreement
+// API used: /v1/payments/billing-agreements/<Agreement-Id>/suspend
+
+// Retrieving the Agreement object from Create Agreement Sample to demonstrate the List
+/** @var Agreement $createdAgreement */
+$createdAgreement = require 'CreateBillingAgreementWithCreditCard.php';
+
+use PayPal\Api\Agreement;
+use PayPal\Api\AgreementStateDescriptor;
+
+//Create an Agreement State Descriptor, explaining the reason to suspend.
+$agreementStateDescriptor = new AgreementStateDescriptor();
+$agreementStateDescriptor->setNote("Suspending the agreement");
+
+try {
+
+    $createdAgreement->suspend($agreementStateDescriptor, $apiContext);
+
+    // Lets get the updated Agreement Object
+    $agreement = Agreement::get($createdAgreement->getId(), $apiContext);
+
+} catch (PayPal\Exception\PPConnectionException $ex) {
+    echo "Exception: " . $ex->getMessage() . PHP_EOL;
+    var_dump($ex->getData());
+    exit(1);
+}
+
+ResultPrinter::printResult("Suspended the Agreement", "Agreement", $agreement->getId(), $agreementStateDescriptor, $agreement);
+
+return $agreement;